Comparative analysis of flow structure in an axisymmetric vortex chamber using the URANS approach and DNS

A numerical study of the flow in a swirl (tangential) vortex chamber using Direct Numerical Simulation (DNS) and Unsteady Reynolds-averaged Navier–Stokes (URANS) approaches is presented. The three-dimensional flow of a viscous incompressible gas (air) is considered at Reynolds number Re = 3.4·10 4 . The distributions of the axial and tangential velocity components, as well as their fluctuations, are analyzed. It is established that the DNS results provide a distribution of parameters in a swirling flow close to the experimental data, whereas turbulence models based on the Boussinesq hypothesis fail to reproduce the dynamics of a confined swirling flow numerically.